Means of treating aggregate with bitumen



Oc'f". 9, 1934. K. E. MccoNNAuGHAY 1,9755902 MEANS OF TREATING AGGREGATE WITH BITUMBN Filed NOV.` 29, 1929 @3g-MKM?.

Patented a. 9, 1934 MEANS 0F TREATING AGGREGATE WITH BITUMEN Kenneth E. McConnaughay, indianapolis, Intl., as-

signor to Pre Cote Corporation, Indianapolis, Ind., a corporation of Indiana Application November 29, 1929, Serial No. 410,442

This invention relates to means and method of treating aggregate with bitumen and one feature of the invention is the provision of means for coating the aggregate used with a film of bitumen as the aggregate is being moved from a transporting vehicle or a bin to the vehicle in which the treated product is to be conveyed to the roadway or other surface being built.

A further feature of the invention is the prow vision of means for applying the lm of bitumen by the process of immersion and without agitation other than the free movement of the aggregate by gravity, through the bitumen product.

A further feature of the invention is the provision of means for draining the excess of bitumen from the aggregate when removed from the bitumen and before being entered in the conveying vehicle, whereby but a thin film of bitumen will be retained by the aggregate.

A further `feature of the invention is that of providing a paving material which may be manufactured without weighing, grading, or proportioning either the bitumen or aggregate.

A further feature of the invention is in so applying the coating of bitumen that it will form ,a part of the unloading process of the aggregate and greatly increase the output and greatly de-l crease the expense of the operation.

A further feature of the invention is in so arranging the bitumen applying means that any suitable aggregate, of any suitable size or shape, may be treated.

Other objects and advantages will be hereinafter more fully set forth and pointed out in the accompanying speciflcation.

` In the accompanying drawing which is made a part of this application,

Figure 1 is a top plan view of the bitumen applying mechanism. y

Figure 2 is a sectional view thereof as seen along line 22,- Fig. 1; and, A

Fig-ure 3 is a perspective view of one of the buckets used in removing the treated particles from the bitumen emulsion orbath.

Heretofore, the application of a bitumen to an aggregate has been an arduous, slow and expensive operation, and requiring more or less expensive equipment in carrying out the various operao-various objectionable features and provide a f-means and method of coating the aggregate with alm of any suitable bitumen or any of its de- 'ivativea at a minimum expense of time-and grationtions, and it is my main object to overcome these abor las well as equipment in performing thisl any of its allied products, said vat having conveyor buckets 2 traveling through one end thereof for removing the aggregate 3 from the`vat.

The aggregate 3, which is usually conveyed to a suitable unloading point along a railroad, in the usual form of car or gondola 4, is dumped in the usual manner from the car 4, into a trough 5, extending beneath the track rails 6 and which is so arranged that the aggregate will move by gravity to one en'd of the trough, where it is' picked up by any suitable form of conveying 75 belt 7, or similar device.

The aggregate discharges from the end of the belt 7, into a chute 8 and descends therethrough into one end of the vat 1 and, owing to the inclination of the bottom of the vat, moves by gravity to the opposite end of the vat, where it is picked up by the conveyorbuckets 2 and' carried to a chute 9, from whence it discharges into a truck or vehicle body 10, employed for conveying the treated particles yto the road, street or other surface being laid. 'I'he emulsion or fluid bitumen is of such a depth within the vat 1, that all the particles of aggregate entering the vat will be entirely immersed in and 'coated with a lm of bitumen, and 90 in order to remove yall excess bitumen from the particles of aggregate, while being elevated by the conveyor buckets and before being discharged into the vehicle body 10, the buckets 2 are provided with a plurality of perforations 11, through which the excess of bitumen will drain from the particles of aggregate and return into the vat 1.

By treating the aggregate in this manner, no excess of bitumen will be carried over the top of the chainof conveyor buckets into the vehicle body, but each particle of aggregate will be thoroughly covered with auniform thin coating of bitumen.

It will be noted from the drawing that the con veyor buckets 2 dip completely to the bottom of 105 the vat 1, the vat-bottom being so shaped as to conform closely to the path of the lips of the buckets 2. As the result of this arrangement, it is substantially impossible for any particles of aggregate to remain in the vat 1 for any extend- 110 of production.

ed length of time, and it is impossible for aggregate to collect and lie quiescentl in the bitumen bath. This feature is of considerable importance, especially when the coating bath in the vat 1 is in the form of an aqueous emulsion of bitumen; for I nd that if the conveyor does not remove aggregate from the lowest Vpoint of the vat there develops a marked tendency for the bituminous emulsion in the vat to break down. I believe this to be due to the action of fine aggregate particles in upsetting the equilibrium conditions which are necessary to the maintenance of the bitumen in an emulsifying state.

Although I have shown the aggregate as being unloaded from a car, treated with the bitumen and then discharged into a vehicle to be transported, it will be clearly understocdthat the aggregate may be taken from a bin or other suitable source, and after being treated, entered into la vehicle or returned to another storage bin.v

' It will likewise be seen that any suitable aggregate may be used, such as shale, limestone, slag, gravel, granite, sand, shell, cinders, or any and all other mineral aggregates and that the emulsion or uid used for treating the aggregate,

may consist of hot asphalt, cut back asphalt,

asphalt emulsions, hot tar, or any and all other bitumen bearing materials.

It will likewise be seenvthat a perfect lm of bitumen may be applied to aggregates of varying dimensions and that a larger sized aggregate may be treated successfully, than has been possible heretofore and at a far less expense in time and labor as well as in the cost of preparation of the.

material and in theA expensive machinery required to accomplish the object when other methods are used. l

It will further be seen that the aggregate may be treated successfully without any manual handling thereof, thus greatly reducing the cost What I claim is: 1. A device for coating particles of aggregate with a-bituminous binder, comprisingl a vat adapted to contain a supply of emulsied binder and to receive aggregate to be coated, and a conveyor for removing from the said vat aggregate which hasbeen treated with said binder, said conveyor comprising an endless belt and spaced conveyor buckets mounted thereon, said buckets being provided with openings to permit excess binder to drain back into the vat as the aggre-v gate is removed therefrom, said vat having a curved bottom conforming to the path of travel of said buckets, said conveyor being positioned so that said buckets, at their lowest point of travel, move substantially in contact with said bottom to prevent accumulation of aggregate particles in the vat and any resultant tendency to break the emulsion.

2. A device for coating particles of aggregate with a bituminous binder, comprising a vat adapted to contain a supply of emulsiled binder and to receive aggregate to be coated, and a conveyor for removing from said vat aggregate which has been treated with said binder, said conveyor comprising a rotating element located in said vat, an endless belt passing around said rotating element, and spaced conveyor buckets carried by said endless belt and having tangentially directed aggregate-receiving and aggregate-discharging openings, said buckets being provided with openings to permit excess binder to drain back into the vat as the aggregate is removed therefrom, said vat having a curved bottom the lowest point of which is substantially in the vertical plane through the axis of said rotating element, said curved bottomconforming 'to the path ofk travel 105 of said buckets, the radial distance between the axis of said rotating element and a bucket passing therearound being substantially equal to the distance between such axis Aand the vat-bottom, whereby said buckets will remove-aggregate from im the lowest point of the vat to prevent accumulation of aggregate particles in the vat and any reparticles.

KENNETH E. MCCONNAUGHAY. 

